4. Chords

Chords are composed of multiple notes harmonizing at same time.

Here lists are built up so chords will contain more intervals.

For example, for the dyad, the interval is 7 semitones.

The printouts will show the six created lists.

In the measure function, we iterate over all notes in a list and add a note for 3 of the 4 beats at the 6 different measures.

# mus4.py
# Chords

import music21 as m21
from writeMIDI import writeMIDI

# beats per minute
bpm = 130

notes = []

# dyad
m1 = ['C3','G3']
# triad
m2 = m1 + ['E4']
# tetrad
m3 = m2 + ['B3']
# pentad
m4 = m3 + ['F#4']
# hexad
m5 = m4 + ['A4']
# heptad
m6 = m5 + ['D5']

# lists
print('m1 =',m1)
print('m2 =',m2)
print('m3 =',m3)
print('m4 =',m4)
print('m5 =',m5)
print('m6 =',m6)

def measure(meas,m):
    for n in m:
        notes.append((n,4*meas,3,115))
        
measure(0,m1)
measure(1,m2)
measure(2,m3)
measure(3,m4)
measure(4,m5)
measure(5,m6)

key = 'C'
writeMIDI(key,"piano",bpm,notes,'mus4')

PrintOut:

m1 = ['C3', 'G3']
m2 = ['C3', 'G3', 'E4']
m3 = ['C3', 'G3', 'E4', 'B3']
m4 = ['C3', 'G3', 'E4', 'B3', 'F#4']
m5 = ['C3', 'G3', 'E4', 'B3', 'F#4', 'A4']
m6 = ['C3', 'G3', 'E4', 'B3', 'F#4', 'A4', 'D5']

This will generate this for mus4.mid:

Or piano roll: (The only view given from now on):